The invention relates to a self-adjusting boat trailer cradle for launching, hoisting and transportation of small boats.
In recent years boat trailers have been developed by means of which motor-boats and sailboats may be loaded and transported from the site to the launching site. Frequently, a small-boat trailer is built as a small slipway which may be wheeled downward into the water with the boat loaded thereon until the boat is launched and its lashings may be removed. One type of boat trailer comprises a two- or four-wheeled cart or carriage having a rectangular chassis frame and a pair of longitudinally extending girders upon which keel rollers are mounted. In the vicinity of the two rear corners of the chassis frame, or all the four corners of a carriage, vertically adjustable stanchions are provided by means of which the boat can be shored subsequently to its hauling up onto the trailer with the keel rolling on the keel rollers. At the ends of the stanchions plates are pivotally mounted so that they may adapt themselves to the shape of the hull.
A boat trailer of the described type and other similar types suffers from the disadvantage that it demands a time-consuming readjustment of the hull stanchions each time when a boat will be loaded and unloaded. A further disadvantage resides in the fact that in the course of its loading or unloading, the boat could be damaged by the hull stanchions and, in turn, these could be damaged by the boat. Admittedly, the construction has been improved by replacing the plates of the hull stanchions with rubber-tired wheels so that the boat will not be damaged. Despite the soft reception afforded by the rubber-tired wheels it has turned out, however, that the hull stanchions may be deformed, or that the rubber tires may be pulled off their rims through unskilled or careless handling.
On account of the shortcomings reported above a main object of the present invention is to provide an automatically adjustable boat trailer cradle which does not need any readjustments as soon as a boat is to be transported, and which cannot damage the boat and cannot itself be damaged by the boat.